Interpretation of Microbial Soil Indicators as a Function of Crop Yield and Organic Carbon

Resumo -O objetivo deste trabalho foi avaliar os efeitos de diferentes usos da terra nas características e nos atributos de Latossolos da região Oeste do Estado da Bahia. Os Latossolos apresentavam texturas com fração areia amplamente predominante, e foram avaliados em áreas de cerrado, algodão, soja e feijão, no Município de Luís Eduardo Magalhães. A caracterização morfológica e a coleta de amostras de solos para avaliação dos atributos físicos e químicos por horizontes foram feitas em minitrincheiras, enquanto a avaliação da condutividade hidráulica saturada foi feita com permeâmetro de Guelph em duas profundidades: 0,0-0,20 e 0,20-0,40 m. Os Latossolos avaliados, além de uma estrutura maciça, apresentaram horizonte genético adensado, que, sob uso agrícola, torna-se mais compactado, espesso e superficial, e forma torrões quando revolvido. O uso agrícola reduz a condutividade hidráulica saturada dos Latossolos avaliados nas duas camadas, com exceção do cultivo de feijão.Termos para indexação: Cerrado, camada adensada, compactação de solo, condutividade hidráulica saturada, permeâmetro de Guelph, solos leves. Characteristics and attributes of Oxisols under different land uses in the western region of the state of Bahia, BrazilAbstract -The objective of this work was to evaluate the effects of different land uses on the characteristics and attributes of Oxisols in the western region of the state of Bahia, Brazil. The Oxisols had textures with largely predominant sand fraction, and they were evaluated in areas of cerrado, cotton, soybean, and common bean in the municipality of Luís Eduardo Magalhães. The morphological characterization and the collection of samples for evaluating soil physical and chemical attributes of horizons were carried out in small trenches, while the evaluation of field saturated hydraulic conductivity was done using the Guelph permeameter at two depths: 0.0 to 0.20 and 0.20 to 0.40 m. The evaluated Oxisols, besides their massive structure, showed a dense genetic horizon, which, under agricultural use, becomes more compacted, thick, and shallow, forming clods when plowed. Agricultural use reduces the saturated hydraulic conductivity of the evaluated Oxisols in both layers, except for common bean cultivation.

Section: Resultsunclassified

Características e atributos de Latossolos sob diferentes usos na região Oeste do Estado da Bahia

Fontana

Teixeira

Balieiro

et al. 2016

“…This might be the reason for the higher accumulation of MBC in the continuous pasture, in comparison with the other systems. Furthermore, the microbial biomass in the continuous pasture was less dynamic and more dormant, showing the lowest basal respiration levels (Table 4) (Singh & Ghoshal, 2014 According to Lopes et al (2013), the MBC values in the 0.00-0.10-m layer obtained in the present study were adequate for soils under cerrado (>405 mg kg -1 ), but moderate for those under the ICLS, ICLFS, and continuous pasture (206-405 mg kg -1 ). It must be highlighted that in the ICLS and deeper soil layers (0.10-0.20 and 0.20-0.30 m), MBC values were considered adequate, according to the same classification, indicating that the ICLS improved soil quality, at least up to 0.20-0.30 m.…”

Section: Resultsmentioning

confidence: 56%

“…Soil microbial biomass (SMB) is a dynamic labile fraction of soil organic matter that is very sensitive to changes in soil management (Jackson et al, 2003). Highly productive Brazilian Oxisols often have high levels of microbial biomass, associated with higher levels of soil organic matter, resulting in higher soil quality (Lopes et al, 2013). Muniz et al (2011) reported that the recovery of degraded pastures by implementing ICLS on Oxisols increased microbial biomass carbon (MBC), even when compared with native cerrado (Brazilian savanna vegetation).…”

Section: Introductionmentioning

confidence: 99%

Dynamics of soil microbiological attributes under integrated production systems, continuous pasture, and native cerrado

Oliveira¹,

Ramos

Carvalho

et al. 2016

-The objective of this work was to evaluate the dynamics of soil microbiological attributes under integrated production systems, continuous pasture, and native cerrado. The study was conducted in a transition area from crop to livestock. Four areas with different land uses were evaluated: an integrated crop-livestockforestry system (ICLFS), cultivated with Eucalyptus urograndis alley cropping, spaced 2x2 m between plants and 22 m between alleys; an integrated crop-livestock system (ICLS

“…The upper and lower threshold values, equivalent to the maximum and minimum values, were defined by specific technical and scientific recommendations for tropical soils (Kiehl, 1998;Ribeiro et al, 1999;Sousa & Lobato, 2004;Blainski et al, 2008;Lopes et al, 2013).…”

Section: Methodsmentioning

confidence: 99%

“…McBratney et al (2014) introduced the more complex concept of 'soil security', which deals with the conservation and improvement of the soil resources to produce food, fiber, freshwater, energy, and to help maintaining the climate sustainability and biodiversity. Nowadays, the research focus is on selecting, weighting, and interpreting a consensual set of indicators to assess soil quality (Lopes et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Selecting soil quality indicators for different soil management systems in the Brazilian Cerrado

Stefanoski

Figueiredo

Santos

et al. 2016

-The objective of this work was to assess soil quality indicators obtained with different datasets to compare soil management systems in the Brazilian Cerrado. Three criteria were used to select soil physical, chemical, and biological indicators: the full set of indicators obtained, with 36 parameters, for which all the physical, chemical, and biological soil properties were determined; a subset of indicators selected by principal component analysis (20 parameters); and a subset of indicators with some frequency of use in the literature (16 parameters). These indicators were obtained from the following management systems: no-tillage, conventional tillage, and native cerrado vegetation. Soil samples were collected at 0.0-0.1-m soil depth, and soil quality indicators were subjected to analysis of variance and their means were compared. The incorporation of soil native cerrado into agriculture decreased soil quality. The most commonly used indicators in the scientific literature are sensitive enough to detect differences in soil quality according to land use. Therefore, the selection of a minimum set of representative data can be more useful than a complex set of properties to compare management systems as to their soil quality.Index terms: no-tillage, principal component analysis, soil functioning, soil health, soil management, soil security. Seleção de indicadores da qualidade do solo para diferentes sistemas de manejo do solo no CerradoResumo -O objetivo deste trabalho foi avaliar indicadores da qualidade do solo, obtidos de diferentes bases de dados, para comparar sistemas de manejo do solo no Cerrado. Três critérios foram utilizados para a seleção de indicadores físicos, químicos e biológicos do solo: o conjunto completo de indicadores obtido, com 36 parâmetros, entre os quais todas as propriedades físicas, químicas e biológicas foram determinadas; um subconjunto de indicadores selecionados por análise de componentes principais (20 parâmetros); e um subconjunto de indicadores com alguma frequência de uso na literatura (16 parâmetros). Esses indicadores foram obtidos a partir dos seguintes sistemas de manejo: plantio direto, preparo convencional e cerrado nativo. As amostras de solo foram coletadas a 0,0-0,1 m de profundidade, e os indicadores de qualidade do solo foram submetidos à análise de variância e suas médias foram comparadas. A incorporação do solo de cerrado nativo à agricultura diminuiu a qualidade do solo. Os indicadores mais comumente utilizados na literatura científica são suficientemente sensíveis para detectar diferenças de qualidade do solo de acordo com o uso da terra. Portanto, a seleção de um conjunto mínimo de dados representativos pode ser mais útil do que um conjunto complexo de atributos, para comparar sistemas de manejo quanto à qualidade do solo.Termos para indexação: plantio direto, análise de componentes principais, funcionamento do solo, saúde do solo, manejo do solo, segurança do solo.